chore: 提交当前变更

src/Infrastructure/TakeoutSaaS.Infrastructure/Dictionary/Services/DistributedDictionaryCache.cs

@@ -0,0 +1,56 @@
+using System.Text.Json;
+using Microsoft.Extensions.Caching.Distributed;
+using Microsoft.Extensions.Options;
+using TakeoutSaaS.Application.Dictionary.Abstractions;
+using TakeoutSaaS.Application.Dictionary.Models;
+using TakeoutSaaS.Infrastructure.Dictionary.Options;
+
+namespace TakeoutSaaS.Infrastructure.Dictionary.Services;
+
+/// <summary>
+/// 基于 IDistributedCache 的字典缓存实现。
+/// </summary>
+public sealed class DistributedDictionaryCache : IDictionaryCache
+{
+    private readonly IDistributedCache _cache;
+    private readonly DictionaryCacheOptions _options;
+    private readonly JsonSerializerOptions _serializerOptions = new(JsonSerializerDefaults.Web);
+
+    public DistributedDictionaryCache(IDistributedCache cache, IOptions<DictionaryCacheOptions> options)
+    {
+        _cache = cache;
+        _options = options.Value;
+    }
+
+    public async Task<IReadOnlyList<DictionaryItemDto>?> GetAsync(Guid tenantId, string code, CancellationToken cancellationToken = default)
+    {
+        var cacheKey = BuildKey(tenantId, code);
+        var payload = await _cache.GetAsync(cacheKey, cancellationToken);
+        if (payload == null || payload.Length == 0)
+        {
+            return null;
+        }
+
+        return JsonSerializer.Deserialize<List<DictionaryItemDto>>(payload, _serializerOptions);
+    }
+
+    public Task SetAsync(Guid tenantId, string code, IReadOnlyList<DictionaryItemDto> items, CancellationToken cancellationToken = default)
+    {
+        var cacheKey = BuildKey(tenantId, code);
+        var payload = JsonSerializer.SerializeToUtf8Bytes(items, _serializerOptions);
+        var options = new DistributedCacheEntryOptions
+        {
+            SlidingExpiration = _options.SlidingExpiration
+        };
+        return _cache.SetAsync(cacheKey, payload, options, cancellationToken);
+    }
+
+    public Task RemoveAsync(Guid tenantId, string code, CancellationToken cancellationToken = default)
+    {
+        var cacheKey = BuildKey(tenantId, code);
+        return _cache.RemoveAsync(cacheKey, cancellationToken);
+    }
+
+    private static string BuildKey(Guid tenantId, string code)
+        => $"dictionary:{tenantId.ToString().ToLowerInvariant()}:{code.ToLowerInvariant()}";
+}